<!DOCTYPE html>
<html>

<head>
    <style>
        body {
            width: 200px;
            height: 400px;
        }

        button {
            height: 30px;
            outline: none;
        }
    </style>
</head>

<body>
    <header>
        <div>AlexYang的Chrome插件</div>
    </header>

    <button id="changeColor" value="切换颜色">convert</button>
    <script src="popup.js"></script>
</body>

</html>